Figure 11. 



100 



WIGE0N AND PINTAIL DAYS OF USE 



ILLINOIS RIVER 



POOL 26 



WIGEON 



PINTAIL 



1958 ' 60 i 62 I 64 ' 66 

 59 61 63 65 67 



69 7 ° 71 72 73 ^ 75 76 77 



YEARS 



154 



